Writing implement

ABSTRACT

A writing implement is disclosed in which a nib holder provides a tortuous air passageway between the exterior of the writing implement and an ink reservoir in its interior. The nib holder includes a stem, a frusto-conical tip, and at least one raised rib surrounding the stem and spaced apart from the tip. Through the center of the frusto-conical tip and stem there is a hollow passageway in which a writing nib is securely fitted. The nib holder fits into the front end of the barrel of the writing implement; and the tip, the rib, the interior of the barrel, and a portion of the stem cooperate to form a small air chamber in the writing implement. Another passageway in the tip provides for the communication of air between the exterior of the writing implement and the air chamber and a passageway in the rib provides for the communication of air between the air chamber and the remainder of the interior of the writing implement. The points at which the two passageways enter the air chamber have a different angular orientation with respect to the axis of the stem, thereby providing a tortuous air passage that minimizes any ink leakage from the interior of the writing implement.

22 Filed:

United States Patent 91 Rich [ WRITING IMPLEMENT Claude R. Bich, 152 Rue de Paris, Montreuil, France Oct. 4, 1972 [21] Appl. No.: 294,888

Related US. Application Data [63] Continuation-in-part of Ser. No. 288,295, Sept 12,

1972, abandoned.

[76] Inventor:

Primary ExaminerLawrence Charles Attorney-Dean S. Edmonds et al.

[451 Dec. 4, 1973 [57 ABSTRACT A writing implement is disclosed in which a nib holder provides a tortuous air passageway between the exterior of the writing implement and an ink reservoir in its interior. The nib holder includes a stem, a frustoconical tip, and at least one raised rib surrounding the stem and spaced apart from the tip. Through the center of the frusto-conical tip and stem there is a hollow passageway in which a writing nib is securely fitted. The nib holder fits into the front end of the barrel of the writing implement; and the tip, the rib, the interior of the barrel, and a portion of the stem cooperate to form a small air chamber in the writing implement. Another passageway in the tip provides for the communication of air between the exterior of the writing implement and the air chamber and a passageway in 11 Claims, 14 Drawing Figures PATENTED BEE 4 SHEEI 10F 3 PATENTED 4 I975 SHEET 2 IF 3 WRITING IMPLEMENT BACKGROUND OF THE INVENTION This is a continuation-in-part of my application Ser. No. 288,295 filed Sept. 12, 1972 for a Writing Implement now abandoned.

In recent years numerous writing implements have been devised that have an extremely simple structure including a barrel, an ink reservoir, a porous writing nib, and a nib holder. Initially, the nib was made of felt and the writing implement was used to provide a broad brush stroke. More recently, porous plastics such as nylon and polyvinyliden'e-fluoride have been used as the nib in general purpose writing implements that compete with'ball-point pens.

Successful operation of these writing implements requires that their interior air pressure be equalized with the exterior air pressure because they operate by capillary attraction of the ink in the nib to the surface on which they are used. There are numerous techniques for providing an air passage to the interior of the writing implement; but 'present designs often increase the cost of the writing implement or do not prevent ink spillage. Because of the extremely high volumes of writing implements that are sold annually, any reduction in the unit cost of manufacture of these writing implements represents significant annual savings in manufacturing costs; and, as might be expected, leakage is not acceptable to the user of the writing implement.

SUMMARY OF THE INVENTION To prevent ink leakage while maintaining low manufacturing costs, I have devised a nib holder that provides a tortuous air passageway between the exterior of the writing implement and the ink reservoir in its interior. This is accomplished in an illustrative embodiment of my invention by a nib holder that comprises a stem, a frusto-conical tip, and at least one raised rib surrounding the stem and spaced apart from the tip. In the center of the stem and frusto-conical tip is a hollow passageway in which the writing nib is securely fitted. The nib holder fits into the front end of the barrel of the writing implement; and the rib, the tip, the interior of the barrel, and a portion of the stem cooperate to form a small air chamber in the device. Another passageway in the tip provides for the communication of air between the exterior of the writing implement and the air chamber. A passageway in the rib provides for the communication of air between the air chamber and the remainder of the interior of the writing implement. The points at which the two passageways enter the air chamber have a different angular orientation with respect to the axis of the stem, thereby providing a tortuous air passage that minimizes any ink leakage from the interior of the writing implement.

In a preferred embodiment of my invention, a second rib surrounds the stem and is spaced apart from the first rib. The two ribs, the interior of the barrel, and a portion of the stem cooperate to form a second air chamber in the writing implement; and the passageway from the first air chamber through the first rib enters the second air chamber. In the second rib there is another passageway that provides for communication of air between the second air chamber and the remainder of the interior of the writing implement. The points at which the two passageways enter the second air chamber have a different angular orientation with respect to the axis of the stem, thereby providing an additional twist in the air passage to the interior of the writing implement.

Preferably, the air passageway through the second rib is a slot that is continued, in the form of a recess in the stem, through the second air chamber to the first rib. In the first rib there is a hollow portion at the end of this recess that forms a pocket in which ink can be collected. This pocket serves as a trap to gather any loose ink and thereby provides further protection against ink leakage.

The tip and stem are adapted to support the nib in all directions. In the hollow passageway of the frustoconical tip in which the nib is fitted, there is a shoulder that cooperates with a tapered portion toward the forward end of the nib to support the nib against motion into the writing implement. The nib is designed to be slightly larger than the hollow interior of the nib holder. As a result, the nib is tightly held in place in the nib holder and prevented from falling out. Sideways movement of the nib is prevented by causing the frustoconical tip and stem to extend along most of the length of the nib.

At the end of the stem removed from the frustoconical tip, there is an annulus through which the nib protrudes. This annulus supports the nib so that it is po sitioned approximately on the axis of the ink reservoir. In addition, it cooperates with a set of shoulders on the inside of the barrel to define a supporting surface beyond which the ink reservoir cannot move. This insures that the nib only extends a short distance into the ink reservoir. At the same time, spaces between the annulus and the shoulders on the inside of the barrel permit the passage of air to the ink reservoir. Additional air passageways are provided along the length of the ink reservoir by appropriate design of the shape of the ink reservoir and the interior of the barrel.

BRIEF DESCRIPTION OF THE DRAWING These and other objects, features, and elements of my invention will be'more readily apparent from the following detailed description of the drawing in which:

FIG. 1 is a longitudinal cross-sectional view of an illustrative writing implement embodying my invention;

FIGS. 2 and 3 are top and side views, respectively, of an illustrative nib holder of my invention;

FIG. 4 is a longitudinal cross-sectional view of the illustrative nib holder of my invention;

FIG. 5 is a transverse cross-sectional view of the illustrative nib holder of my invention;

FIG. 6 is a longitudinal cross-sectional view of an illustrative barrel of my invention;

FIGS. 7, 8, and 9 are transverse crosssectional views of an illustrative barrel of my invention;

FIG. 10 is a cross-sectional view depicting the relationship between the writing nib and the ink reservoir in the writing implement of my invention;

FIG. 11 is a longitudinal view, partly in section, of a second embodiment of the illustrative nib holder of my invention; and

FIGS. 12, 13, and 14 are transverse cross-sectional views taken at different points in the embodiment shown in FIG. 11.

DETAILED DESCRIPTION OF THE DRAWING An illustrative writing implement 10 of my invention is shown in FIG. 1. Writing implement 10 comprises a barrel 20; an ink reservoir 25, a nib 30, a nib holder 35,

and a plug all in axial alignment within the barrel; and a cap 45. The writing implement illustrated in FIG. 1 is substantially the same as the Bic Banana Fine Line Marker presently being marketed in the United States.

The relationship between nib holder 35 and the other elements of the writing implement is detailed in FIG. 2 and the various features of the nib holder will be apparent from a consideration of FIGS. 2-5. Nib holder 35 comprises a stem 50, a frusto-conical tip 55, and first and second ribs and 65. Two ribs 60, are used to assure axial alignment of the nib holder in the barrel. Preferably, ribs 60 and 65 have slightly larger diameters than the interior of barrel 20 to provide a press fit of the nib holder inthe barrel. To facilitate the insertion of the nib holder into the barrel, the diameter of rib 65 is slightly smaller than that of rib 60 and the rearward side of rib 65 is beveled. In the center of the stem and tip is a passageway 130 in which nib 30 is securely held. The forward end of nib 30 is held against motion into the writing implement by a shoulder 56 that engages a tapered portion 31 of the nib.

Rib 60, tip 55, a portion of stem 50, and the interior of barrel 20 define a first air chamber in the interior of the writing implement. Ribs 60 and 65, another portion of stem 50, and the interior of barrel 20 define a second air chamber in the writing implement. A first passageway in the rearmost portion of tip 55 provides for the communication of air between the exterior of the writing implement and the first air chamber. Typically, an identical passageway is located in the rearmost portion of the tip on its opposite side, 180 removed from that shown in FIG. 2. Two second passageways provide for the communication of air between first and second air chambers 70 and 75. A third passageway provides for the communication of air between the second air chamber and the remainder of the interior of the writing implement. The points at which the different air passageways enter the air chamber have a different angular position with respect to the axis of the'stem. Thus, as will be apparent from a consideration of FIGS. 2-5, the minimum angular displacement between a second passageway 85 and either a first or a third passageway 80 or 90 is greater than approximately 40. As a result, a tortuous path is provided for air flow from the exterior of the writing implement to the interior. This provides an extremely long path thru which ink must flow in order to escape from the writing implement, thereby greatly enhancing the chance that any ink will dry up on the surface of the stem. At the same time, any capillary action permitting the flow of ink along the interface between the nib holder and the barrel is broken by the first and second air chambers. in addition, air passageway 90, which is a slot through stem 50, is extended through air chamber 75 and a portion of rib 60. This produces a notch in rib 60 that cooperates with the interior of barrel 20 to form a pocket in which ink may be trapped. This further contributes to prevent any ink leakage through the air passage.

At the end of stem 50 removed from tip 55 there is an annulus through which the nib protrudes. The annulus supports the nib so that it is positioned approximately on the axis of the ink reservoir as shown in FIG. 10. In addition, the annulus cooperates with a set of shoulders shown in FIGS. 6, 7, and 8 on the inside of the barrel to define a forward supporting surface beyond which ink reservoir 25 cannot slide. At the other end of the ink reservoir, the interior side of plug 40 defines a rearward support beyond which ink reservoir cannot move. This insures that the rearward end 32 of nib 30 extends only a short distance into ink reservoir 25 as suggested by FIG. 10. As a result, the position of the nib in the ink reservoir is fixed within desired bounds; and ink flow through the nib, which is a function of the surface area of the nib in contact with the ink reservoir, is controlled. In the preferred embodiment of the Bic Banana Fine Line Marker, the nib extends about 6 millimeters beyond the annulus. For the last 2 millimeters it is buried in the ink reservoir leaving a gap of 4 millimeters between the annulus and the ink reservoir. As shown in FIG. 8, there is some space between annulus 105 and shoulders 110. This space permits the passage of air to ink reservoir 25. Additional air passageways shown in FIG. 9 extend along the length of ink reservoir 25 to insure a substantially uniform air pressure throughout the ink reservoir. Passageways 1 15 are located in the niches formed between the generally cylindrical ink reservoir and three flat surfaces on the interior of barrel 20.

I prefer to form the barrel of polystyrene and the nib holder of Delrin acetal resin; and I use an inkimpregnated polyester fiber cylinder as an ink reservoir. Apparatus is available for forming these parts in relatively inexpensive high volume production. Some of the construction details of the nib holder may be varied to suit the requirements of the particular mold and machine used to produce the nib holder. For example, in the apparatus presently being used, a portion of the stem between the second rib 65 and annulus 105 is reduced to expose part of nib 30. The nib holder, however, could be formed in other molds so that the nib is not exposed. In some cases, it may be desirable to use one rib on the stem instead of two. Although such a nib holder would not be as stable as one with two ribs in contact with the interior of the barrel, my invention may still be practiced by ensuring that there is angular displacement between the points at which the air passageways enter the air chamber between the rib and the tip. The shapes of the various air passageways in the tip and ribs can also be varied from the slots and notches shown; and the angular displacements of the points at which they enter the various air chambers need not be those described above. However, to provide a tortuous air passageway, there must be at least some angular displacement between the passageways entering at least one of the air chambers.

A second embodiment of the nib holder of my invention is shown in FIGS. 11-14. Because this nib holder is quite similar to that shown in FIGS. 2-5, similar elements bear the same numbers incremented by 200. As is apparentfrom FIG. 11, the nib is not exposed at any point in the length of the nib holder. In addition, air passageways 285, 290 through ribs 260, 265 are each a single notch in the rib. These notches as shown in FIGS. 13 and 14 are approximately 180 apart so that the minimum angularseparation between the closest points in the notches is greater than approximately Furthermore, as will be apparent from the consideration of FIGS. 12 and 13, the minimum angular separation between passageway 280 in the rearmost portion of tip 255 and passageway 285 in rib 260 is greater than approximately 40. Consequently, a tortuous air passageway is provided from the exterior of the writing implement to its interior through air passageways 280,

285, 290 and the air chambers 270, 275 defined between tip 255 and ribs 260, 265.

As will be apparent to those skilled in the art, numerous other modifications may be made to the preferred embodiments described and illustrated herein without departing from the scope of the invention as defined in the claims.

What is claimed is:

1. In a writing implement including a barrel, a nib, and an ink reservoir, a nib holder comprising:

a stem having a hollow passageway that extends along the axis of the stem and is adapted to receive the nib;

a tip at one end of the stem, said tip containing a hollow passageway that is a continuation of the passageway in the stem and is likewise adapted to receive the nib;

a first annular rib extending outwardly of the stem portion and engaging the interior surface of the barrel, said rib being spaced on the stem apart from the tip to define a first air chamber between the rib, the tip, an interior surface of the barrel, and a portion of the stem;

a passageway in said tip permitting the communication of air between the exterior of the writing implement and the air chamber; and

a passageway in said rib permitting the communication ofair between the air chamber and the remainder of the interior of the writing implement, said air passageway entering the air chamber at a point that has a different angular position with respect to the axis of the stem than that at which the air passageway in the tip enters the air chamber, whereby a tortuous passageway is provided between the exterior and interior of the writing implement that permits thepassage of air while minimizing ink leakage.

2. The nib holder of claim 1 further comprising means for supporting the forward end of the nib against movement into the writing implement.

3. The nib holder of claim 1 wherein a shoulder in the hollow passageway through the tip cooperates with a tapered portion of the nib to prevent motion of the nib into the writing implement.

4. The nib holder of claim 1 further comprising:

a second annular rib extending outwardly of the stern portion and engaging the interior surface of the barrel, said rib being spaced on the stem apart from the first rib to define a second air chamber between the first and second ribs, an interior surface of the barrel, and a portion of the stem; and

a passageway in said second rib permitting the communication of air between the second air chamber and the remainder of the interior of the writing implement.

5. The nib holder of claim 4 wherein the passageway in the first rib enters the second air chamber at a point that has a difi'erent angular position with respect to the axis of the stem than that at which the passageway in the second rib enters the second air chamber.

6. The nib holder of claim 1 further comprising an annulus at the end of the stem removed from the tip that cooperates with a set of shoulders defined in the interior of the barrel to prevent movement of the ink reservoir beyond said annulus.

7. The nib holder of claim 6 wherein the annulus defines an end of the hollow passageway and causes the 6. nib to be positioned on approximately the axis of the ink reservoir.

8. The nib holder of claim 1 wherein a portion of said tip, located at the point where the tip joins the stem, extends beyond said stem transversely to the axis of the stem and butts against an open end of the barrel of the writing implement.

9. The nib holder of claim 8 wherein the tip is frustoconical in shape.

10. A writing implement comprising:

a barrel;

a nib;

an ink reservoir; and

a nib holder, said nib holder further comprising:

a stem having a hollow passageway that extends along the axis of the stem and is adapted to re- A ceive the nib;

a tip at one end of the stem, said tip containing a hollow passageway that is a continuation of the passageway in the stem and is likewise adapted to receive the nib;

a first annular rib extending outwardly of the stem portion and engaging the interior surface of the barrel, said rib being spaced on the stem apart from the tip to define a first air chamber between the rib, the tip, an interior surface of the barrel, and a portion of the stem;

a passageway in said tip permitting the communication of air between the exterior of the writing implement and the air chamber; and

a passageway in said rib permitting the communication of air between the air chamber and the remainder of the interior of the writing implement, said air passageway entering the air chamber at a point that has a different angular position with respect to the axis of the stem than that at which the air passageway in the tip enters the air chamber, whereby a tortuous passageway is provided between the exterior and interior of the writing implement that permits the passage of air while minimizing ink leakage.

11. In a writing implement including a barrel, a nib, and an ink reservoir, a nib holder comprising:

a stem;

a tip at one end of the stem;

a first annular rib extending outwardly of the stem portion and engaging the interior surface of the barrel, said rib being spaced on the stem apart from the tip to define a first air chamber between the rib, the tip, an interior surface of the barrel, and a portion of the stern; passageway in said tip permitting the communication of air between the exterior of the writing implement and the air chamber; and a passageway in said rib permitting the communication of air between the air chamber and the remainder of the interior of the writing implement, said air passageway entering the air chamber at a point that has a different angular position with respect to the axis of the stem than that at which the air passageway in the tip enters the air chamber, whereby a tortuous passageway is provided between the exterior and interior of the writing implement that permits the passage of air while minimizing ink leakage.

* i i i 

1. In a writing implement including a barrel, a nib, and an ink reservoir, a nib holder comprising: a stem having a hollow passageway that extends along the axis of the stem and is adapted to receive the nib; a tip at one end of the stem, said tip containing a hollow passageway that is a continuation of the passageway in the stem and is likewise adapted to receive the nib; a first annular rib extending outwardly of the stem portion and engaging the interior surface of the barrel, said rib being spaced on the stem apart from the tip to define a first air chamber between the rib, the tip, an interior surface of the barrel, and a portion of the stem; a passageway in said tip permitting the communication of air between the exterior of the writing implement and the air chamber; and a passageway in said rib permitting the communication of air between the air chamber and the remainder of the interior of the writing implement, said air passageway entering the air chamber at a point that has a different angular position with respect to the axis of the stem than that at which the air passageway in the tip enters the air chamber, whereby a tortuous passageway is provided between the exterior and interior of the writing implement that permits the passage of air while minimizing ink leakage.
 2. The nib holder of claim 1 further comprising means for supporting the forward end of the nib against movement into the writing implement.
 3. The nib holder of claim 1 wherein a shoulder in the hollow passageway through the tip cooperates with a tapered portion of the nib to prevent motion of the nib into the writing implement.
 4. The nib holder of claim 1 further comprising: a second annular rib extending outwardly of the stem portion and engaging the interior surface of the barrel, said rib being spaced on the stem apart from the first rib to define a second air chamber between the first and second ribs, an interior surface of the barrel, and a portion of the stem; and a passageway in said second rib permitting the communication of air between the second air chamber and the remainder of the interior of the writing implement.
 5. The nib holder of claim 4 wherein the passageway in the first rib enters the second air chamber at a point that has a different angular position with respect to the axis of the stem than that at which the passageway in the second rib enters the second air chamber.
 6. The nib holder of claim 1 further comprising an annulus at the end of the stem removed from the tip that cooperates with a set of shoulders defined in the interior of the barrel to prevent movement of the ink reservoir beyond said annulus.
 7. The nib holder of claim 6 wherein the annulus defines an end of the hollow passageway and causes the nib to be positioned on approximately the axis of the ink reservoir.
 8. The nib holder of claim 1 wherein a portion of said tip, located at the point where the tip joins the stem, extends beyond said stem transversely to the axis of the stem and butts against an open end of the barrel of the writing implement.
 9. The nib holder of claim 8 wherein the tip is frusto-conical in shape.
 10. A writing implement comprising: a barrel; a nib; an ink reservoir; and a nib holder, said nib holder further comprising: a stem having a hollow passageway that extends along the axis of the stem and is adapted to receive the nib; a tip at one end of the stem, said tip containing a hollow passageway that is a continuation of the passageway in the stem and is likewise adapted to receive the nib; a first annular rib extending outwardly of the stem portion and engaging the interior surface of the barrel, said rib being spaced on the stem apart from the tip to define a first air chamber between the rib, the tip, an interior surface of the barrel, and a portion of the stem; a passageway in said tip permitting the communication of air bEtween the exterior of the writing implement and the air chamber; and a passageway in said rib permitting the communication of air between the air chamber and the remainder of the interior of the writing implement, said air passageway entering the air chamber at a point that has a different angular position with respect to the axis of the stem than that at which the air passageway in the tip enters the air chamber, whereby a tortuous passageway is provided between the exterior and interior of the writing implement that permits the passage of air while minimizing ink leakage.
 11. In a writing implement including a barrel, a nib, and an ink reservoir, a nib holder comprising: a stem; a tip at one end of the stem; a first annular rib extending outwardly of the stem portion and engaging the interior surface of the barrel, said rib being spaced on the stem apart from the tip to define a first air chamber between the rib, the tip, an interior surface of the barrel, and a portion of the stem; a passageway in said tip permitting the communication of air between the exterior of the writing implement and the air chamber; and a passageway in said rib permitting the communication of air between the air chamber and the remainder of the interior of the writing implement, said air passageway entering the air chamber at a point that has a different angular position with respect to the axis of the stem than that at which the air passageway in the tip enters the air chamber, whereby a tortuous passageway is provided between the exterior and interior of the writing implement that permits the passage of air while minimizing ink leakage. 